1. Field of the Invention
This invention relates to a bottom-opening hopper vehicle, especially a freight hopper car. The invention especially relates to side-opening, wrap-around hopper doors on opposite sides of the vehicle and door-operating, power-operated mechanisms for each of these doors to move them between open and closed positions.
2. Description of the Prior Art
The most pertinent prior art is the hopper vehicle disclosed and claimed in copending U.S. patent application Ser. No. 443,217, now U.S. Pat. No. 3,868,913, entitled "Hopper Vehicle" filed on Feb. 19, 1974, by us and Peter W. Becker and Carl E. Becker. That patent application is now allowed and its disclosure is hereby incorporated by reference in this patent applciation.
With respect to other prior art, reference is made to the description of the prior art appearing in that patent application in which there is specific reference to a book and patents. During the prosecution of that copending application other U.S. patents were called to the attention of the examiner. In addition there were four other U.S. patents cited by the examiner but none was deemed by him to affect the patentability of the claims of that copending patent application.
The hopper vehicle of the invention of said copending patent application has a construction that in many respects is the same as the construction of the hopper vehicle of the present invention. As is seen by a comparison of the summary of the invention of that patent application and by the detailed description of a preferred embodiment of the vehicle of that invention, incorporated herein by reference as mentioned above, with the summary of the invention and the detailed description of preferred embodiments, there is a difference between the hopper vehicle of the invention of that copending patent application and the hopper vehicle of the present invention. This difference in the preferred embodiment of the present invention resides primarily in the construction of the door-operating mechanism for each of the door assemblies of the vehicle.
Each door-operating mechanism of the hopper vehicle of that copending patent application includes a lever pivotally mounted at its bottom end on the bottom margin of said door assembly and having adjacent to its bottom end an extension that extends downwardly and toward the central plane of the vehicle and that is constructed to provide a latching lug. The lever is movable between a first position abutting the inside of said door assembly when the door is unlocked and a second position, when the door is closed, at which said extension is at its latching position to lock the closed door assembly. Each door-operating mechanism also includes power means mounted on support means of the supporting structure of the vehicle and operatively connected to said lever to provide a force on said lever in one direction for movement of said lever from said second position to said first position to unlock the door assembly (and subsequently in one preferred embodiment through said lever to provide part of the outer opening movement of said door assembly) and to provide a force in the opposite direction on said lever for return movement of said door assembly to its closed position and subsequent movement of said lever from said first position to said second position.
The door-operating mechanism of the vehicle of said copending patent application also has means operatively connected to said lever to provide against said lever, when in its first position, a sufficient force to prevent movement of said lever from said first position when the power means provides a force in said opposite direction greater than the force of gravity operating on the door assembly for movement of said door assembly to its closed position.
The hopper vehicle also has two locking means, preferably lugs, mounted on said supporting structure in alignment with said levers, each to be engaged by one of said latching lugs provided by said extensions of said levers after said door assemblies are closed and said levers have been moved to their second positions. The locking means and the latching lugs are constructed so that, when each of said levers is in its said first position and the door assembly on which it is mounted is being moved to said closed position, said latching lug clears said locking means with which it is engaged when said lever is moved to its second position after the door is closed.
A second embodiment of the present invention has the door-operating mechanism described above as the construction for the invention of said copending patent application, but the locking lug on each side of the vehicle is mounted on the supporting structure in a manner that it can be moved inwardly from its normal locking position, to which it is biased, in a direction toward the vertical longitudinal central plane of the vehicle in the event that the latching lug provided by the extension of the lever abuts the inclined surface of the locking lug as the door assembly is being closed. This striking of the locking lug by the latching lug could occur if the means connected to said lever to maintain it at its first position while the door is being closed becomes inoperative. In the event of that inoperativeness the lever would be pivoted away from its first position by the power means, when it is providing the force to close the door, so that the latching lug would no longer be in a position to clear the locking lug. This undesirable movement of the lever from its first position at that time does not prevent a closing of the door in this embodiment of the present invention because of this movable mounting of the locking lug whereby, due to its movement inwardly, the latching lug, as the extension of the lever, slides along the inclined outer surface of the inwardly-moved locking lug until the latching lug is beyond the locking lug. Then the locking lug returns to its normal position to which it is biased by means, such as spring means, constituting a part of its mounting means on the supporting structure.
As seen in the disclosure of said copending patent application, incorporated by reference as mentioned above, the vehicle of that invention has preferably an opening in alignment with the top portion of the lever of the door-operating mechanism through which passes an angular extension of the top portion of the lever for the purpose described in that copending application. Furthermore, the preferred construction provides for three-point locking of each door assembly. The lever of each door-operating mechanism is fixedly mounted on torsion means that is rotatively mounted on the bottom margin of the door assembly and horizontally extends from one end of the door assembly to the other end. At the ends of the torsion means that extends from one end of the door assembly to the other end there are mounted latching arms that pivot with the pivotal movement of said lever and when the latter is in its second position these latching arms at the ends of the torsion means engage keepers, i.e., locking lugs mounted on the supporting structure of the vehicle.
A preferred construction of each door-operating mechanism is a construction in which the lever of the door-operating mechanism is a first lever of a toggle assembly. The second lever of the toggle assembly is pivotally connected at one end to the end of the first lever that is not pivotally mounted on the door assembly. The other end of the second lever is pivotally mounted on support means fixedly mounted on the top margin of the door assembly. That support means is constructed to permit axial movement of the second lever. Spring means is mounted on the second lever between that support means and an intermediate portion of the second lever to bias the second lever in a direction away from the pivotal axis of mounting of the second lever on that support means. The spring means thereby constitutes the means operatively connected to the top portion of the first lever to provide the sufficient force against the first lever when it is in its first position to prevent movement of that lever from that position while the power means is moving the door assembly to the closed position. When the first lever is at its first position, the toggle assembly is in a nonlocking overcenter condition that is one side of the plane at which all three pivot axes of the toggle assembly are centered, i.e., in alignment. When the first lever is at its second position, the toggle assembly is in a locking overcenter condition on the other side of that plane. The first overcenter condition is the more important one for utilization of the spring bias action as the spring has sufficent force to maintain the first lever at its first position until the power means through the first lever has completed the pulling of the door assembly toward the closed position.
The first lever of each toggle assembly is pivotally connected to the respective rod of air cylinders constituting the preferred power means for each door assembly. The toggle assembly is also constructed so that it is in the nonlocking overcenter condition until the piston rod is retracted sufficiently to close the door and is then moved to its locking overcenter condition as the piston rod is further retracted. The spring means is always compressed to some extent. The lower portion of the first lever of the toggle assembly is constructed with an extension providing an integral latching lug that, when the door is closed and the piston rod is further retracted, engages a locking lug mounted on the supporting structure of the vehicle, as described earlier.
When the first lever of the toggle assembly is fixedly mounted on a torsion bar linkage that is rotatably supported by the bottom margin of the door and that extends longitudinally in opposite directions, there are latching arms fixedly mounted on the free ends of the torsion bar linkage. Keepers, i.e., locking lugs, are mounted on the supporting structure of the car to be engaged by those latching arms when the door is closed. The overall construction provides an overcenter latching at the ends of the doors when the torsion bar linkage turns the latching arms to engage the corresponding keepers due to the movement of the toggle assembly to its second overcenter condition by the last part of the retraction of the piston rod.